design op• 데이터 종류: 없음 → table(인자만으로 정해지는 연산자 —— 이미지나 데이터 입력을 받지 않습니다)
• 호출: import interferometry; interferometry.csi_design(wavelength_um=0.6, bandwidth_um=0.1, z_range_um=12.0, width_px=640, height_px=480, min_visibility=0.3, step_divisor=8.0)(또는 opsinterferometry.get("csi_design"))
광원 스펙트럼으로부터 정해지는 간섭성 주사계의 축방향 한계.
> 아래 상세 설명은 원문입니다 —— 요약과 제목은 번역되어 있습니다.
The counterpart of :mod:visiondesign for the *vertical* axis: closed-form
answers to the questions asked before any hardware is bought — how localised
is the coherence peak, how finely must the scan step, how many planes is that,
and how much memory does the stack need.
Returned dict:
• `coherence_length_um — (4 ln2 / pi) * lambda^2 / delta_lambda`, the
FWHM of `|gamma(OPD)|` for a Gaussian source (Born & Wolf 7.5.8). This
is a property of the optical path difference. Verified in the tests
against a direct numerical Fourier transform of the Gaussian source
spectrum, at three (lambda, delta_lambda) settings, agreeing to 6
significant figures.
• `envelope_fwhm_um` — half of that: the width of the envelope along
the scan axis, because the double pass makes `OPD = 2z`. This is the
one to hand to :func:csi_signal_simulate /
:func:csi_stack_simulate, and the two are reported separately precisely
because collapsing them into one name called "coherence length" is a clean
factor-of-two error in every height the module produces. (It was one
during development, and the numerical check above is what caught it.)
• `envelope_sigma_um — envelope_fwhm_um` as a Gaussian sigma.
• `fringe_period_um — lambda/2`. The double pass halves it, and this
is the number that makes phase-shifting ambiguous above `lambda/4`.
• `max_z_step_um — lambda/4`. The Nyquist ceiling on the scan step;
:func:csi_peak_position and :func:csi_height_map refuse at or above
it.
• `recommended_z_step_um — lambda/step_divisor` (default lambda/8, the
usual 90-degree-per-plane choice), reported only if it is below the
ceiling.
• `capture_range_um` — the height interval over which the fringe contrast
stays above *min_visibility* of its peak,
`2*sigma*sqrt(2 ln(1/min_visibility))`. Outside it a surface produces
fringes too faint to locate, whatever the scan range is.
• `planes_per_envelope` — how many scan planes fall inside
`envelope_fwhm_um` at the recommended step. Below ~4 the three-point
estimators have nothing to fit.
• `n_planes / stack_elements / stack_megabytes` — the scan you are
about to run and the float64 stack it produces, plus
`stack_within_cap against :data:MAX_STACK_ELEMENTS`. This is the
number people discover after waiting for the scan.
• `phase_unambiguous_step_um — lambda/4`, the largest surface step
phase-shifting interferometry can measure without a fringe-order error.
It is here so the two families can be compared in one place: coherence
scanning has no such limit inside the scan range, and that is the
entire reason to pay for the scan.
What this deliberately does not return is a vertical *repeatability* — a
"resolution" in nanometres. That number depends on the signal-to-noise ratio
and on which of :data:ESTIMATORS you use, the estimators do not even rank
the same way with and without noise, and an attempt to verify the textbook
"two surfaces closer than the coherence length are unresolved" criterion
against this module's own forward model failed: two reflectors 0.4
coherence lengths apart still produce two envelope maxima, because the two
interferograms interfere with each other and the envelope of a sum is not the
sum of the envelopes. Rather than assert a formula that its own tests
contradict, this operator returns only quantities it can verify, and the
measured estimator table lives in the module docstring.
Raises `ValueError`: non-real / non-finite / string / bool parameters, a
non-positive wavelength / bandwidth / range, a *bandwidth_um* at or above
*wavelength_um* (a source whose spectrum reaches zero frequency is not a
quasi-monochromatic source and the coherence-length formula does not apply to
it), a *min_visibility* outside `(0, 1)`, a *step_divisor* below 4 (which
would recommend a step at or past its own Nyquist ceiling), and pixel counts
outside `[1, 65536]`.
• 샘플 데이터 카탈로그(DL URL / 라이선스) —— 2-D 는 skimage.data(BSD/public)+ 합성, 3-D 는 실데이터 소스(Stanford/PDS 등)의 DL URL.
• 연산자의 내력·참고문헌 —— 이 연산자 족의 바탕이 된 연구/기법의 출처.
• 알고리즘의 정전(저자·연도)과 용도는 위의 패밀리 사용 가이드에 적혀 있습니다.
• coherence_scanning — py -3.11 examples/coherence_scanning.py
table 를 입력으로 받는 것)—
design)—
*Provenance: interferometry.py — INTERFEROMETRY 연산자 레지스트리. 이 op 노트는 tools/opdocs.py md 가 자동 생성합니다(직접 편집하지 마세요).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.